i bought a couple of cutting boards when i went to the salcedo market: a round chunk from the trunk of a tamarind tree, and a rectangular one hewn from an acacia tree; i also bought a very nice mortar and pestle made from tamarind wood. all three pieces were had for the very nice price of about US$12.
unfortunately, when i got back to guam, i noticed that there was some cracking in the tamarind wood pieces--i think that the change in altitude/cabin pressure during the flight had something to do it (either drying out the wood, or something else that would cause it to contract and expand). the acacia board did not suffer, but perhaps all the boards could have benefited from a thorough oiling/seasoning before making the flight.
generally, you should oil your untreated wood cutting boards to seal the grain from bacteria, prevent absorption and staining, but it also keeps the wood moisturized and prevents splitting and cracking. you should oil a board thoroughly before you begin using it, and regularly wipe it down to nourish it.
use a neutral food grade oil that will not go rancid. i used mineral oil because it's relatively inexpensive and readily available. all you really need is the oil, a lint-free cloth, and some newspaper.
there are two ways that i know of for oiling a board. the first way is to warm the oil slightly and apply it with a cloth, in the direction of the grain. allow the oil to soak through for several hours, then wipe down any excess oil. apply several more coats (four or five), leaving it to sit between each application.
the other way to set the board on several layers of newspaper, pour the oil liberally onto the wood surface, and leave it to soak overnight. wipe down any excess oil the next morning. after this initial process, apply some oil to the board on a regular basis--monthly if it's used daily, and at your discretion for occasional use.
another advantage? it brings out the grain of the wood beautifully.